Microbiology Final

Salmonella is a gram negative Bacteria. This microbe was the cause of last year’s peanut butter contamination. Which of the following best describes the cell wall structure of Salmonella?

1) Assume 2 Salmonella are introduced into a container of peanut butter. Assume that the conditions ideal for growth of the Salmonella. How many microbes will there be in the peanut butter after 2 hours. Assume the Salmonella has a generation time of 30 minutes in these conditions 2) To answer the above question one must assume that Salmonella divides by

1. Salmonella has the ability to move in a directed manner in its environment. Salmonella must therefore possess

1. When Salmonella moves in a directed manner in response to attractant and repellents in its environment it is exhibiting

1. Lipopolysaccharide plays an important role in the ability of Salmonella to cause disease. Lipopolysaccharide are important structural components of the

1. All Bacteria, including Salmonella, possess a plasma membrane. Which of the following best describes the structure of the plasma membrane in the Bacteria?

1. When Salmonella grow in the presence of oxygen they carry out aerobic respiration. In the absence of oxygen these microbes carry out fermentation. Salmonella would there for be classified as _______________ with respect to oxygen usage.

1. It was recently discovered that Vibrio cholera, the gram negative bacteria that causes the serous disease Cholera, actively secretes a toxin out into its surroundings. Based on your knowledge of the gram negative cell wall this toxin is most likely secreted via

1. 1) The Thermophilic Archaea Pyrodicitiaceae was isolated from a hydrothermal vent in the ocean. This microbe has a specific plasma membrane structure that allows it to survive in extremely high temperatures. Which of the following describes the structure of the plasma membrane in this microbe?
2. 2) The Archaea in the above question are considered gram negative. Which of the following could describes the cell wall structure of these microbes?

1. Lysozyme has the ability to destroy peptidoglycan. It therefore must

1. The high salt concentration in the above question would be a ________________ environment for most microbes.

Most microbes grow in concentrations of NaCl of <1.5%. High NaCl concentrations (much above 1.5%) were once used as preservatives because of salt’s ability to inhibit food- spoiling microbes. Which of the following describes what happens to these microbes in high salt?

1. What is the function of oxygen (O₂) in the metabolism of many bacteria?

1. The Purple Sulfur bacteria in the above question are anoxygenic. Anoxygenic means

1) Purple sulfur bacteria such as Chromatiaceae carry out anoxygenic photophosphorylation to obtain both NADPH and ATP. These microbes use CO₂ as a carbon source. As the name suggests, these microbes accumulate and store elemental sulfur (S). The electron source for photophosphorylation in these Bacteria is therefore 2) The Purple Sulfur Bacteria in the above question are